Egg has several special extra-embryonic membranes ... Other extra-embryonic folds expand up over the embryo to form the amniotic folds. The amnion and chorion develop together as upwardly projecting ...

serpentina (Wiedemann) eggs are described by scanning electron microscopy. A. sororcula eggs present a conspicuous sculpturing of the chorion at the micropylar end while the eggs of A. serpentina are ...

(The chorion is the outer membrane surrounding the ... Yes, mono-di twins are identical – they come from the same fertilized egg that has split. Fraternal twins develop from two separate eggs ...

Chorion forms part of fetal tissue ... Glands may have secreted recognition hormones, moistened the brood area to prevent desiccation of eggs and young Some nutrients may have been in secretions, ...

And sometimes, nature resists. The egg cells of cephalopods, for instance, have a tough, protective coating called a chorion, and glass needles just shatter and break when they hit the surface.